1. Field of the Invention
The invention is concerned with flow valves operated by the angular displacement of a controlling stem.
These valves may be applied, among other area& to the control of flows, especially to the control of one or more flow lines, such as water lines, through little deflections of the controlling stem, in hand washbasins where cold and warm water must be mixed, for example, as well as in the automatic control of mechanisms, etc.
2. Description of the Related Art
A number of valves is well known based--the same as the invention--on a substantially cylindrical body with a flow inlet and a flow outlet, containing a flow sealing element associated with a controlling stem, which--once angularity deflected--produces a flow passing port in the side opposing to the stem pin.
Some of these valves are those described in U.S. Pat. No. 3,698,685, Lang; U.S. Pat. No. 4,320,891, Cairns; U.S. Pat. No. 4,403,570, Freehafer; and U.S. Pat. No. 4,586,464, Agerrley et al. In all these valves, the controlling stem is surrounded by a sealing ring near its inner end and said sealing ring is axially compressed in a lateral portion, a port being thus generated in the totally opposed portion, through which the flow runs in a substantially axial direction to the controlling stem.
This kind of valves is limited to small pressures in the network due to the low sensitivity of the controlling stem. In fact, due to its structure, the network pressure exerts a great force in the stem face located inside the valve body, thus making it necessary a proportionally greater force in the stem in order to control the valve. This disadvantage is even bigger in the designs of the previous art, in which additional axial compression elements are available, such as elastomeric springs or stems.
Another disadvantage of these valves is their little versatility, in the sense that they do not allow the pass of a flow once the deflection action in the controlling stem ends.
Even another disadvantage of these valves is that they may not be used in application requiting inner discharge, that is, these valves are solely destined to discharge the flow through the same opening in which the controlling stem is located, thus pouring the flow coaxially to it.